Range-finder.



Patented Apr. 30, IBM.

-N. TOBIN.

RANGE FINDER.-

(Application filed Nov. 1. 1900.)

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No. 673,099. Pafented A r.'3o, I90l.

. N. TDBIN.

RANGE FINDER.

(Applicltion filed Nov. 1,' 1900.)

(No Model.) I 1 4 Sheets' Sheet 2.

n4: NORRIS PETER-S QQ, pnuvoumm wnsummou. n. c.

No. 673,099, Patented Apr. 30, MN.

N. TOBlN.'.

RANGE FINDER.

(Application filed Nov; 1, 1990.) (No- Model.) 4 Shoets-Shoet 3.

5 1x532? I. I I 3 I I I Atty.

THE NDRRJS PETERS cu. Pwo'm umo" WASHINGTON. o. c.

(No Model.)

Patented Apr. 30, I90I. N. TOBIN.

RANGE FINDER.

A lic ti n filed Nov. 1, 1900.)

4 Shaets$hoot 4.

INVCETOIR An'y.

THE uonms PETERS c0., PNOTO-L XTHDY, WASNINGYON, u. c,

UNITED STATES PATENT OFFICE.

NICHOLAS TOBIN, OF PITTSBURG, PENNSYLVANIA.

RANGE-FINDER.

SPECIFICATION formingpart of Letters Patent No. 673,099, dated April 30,1901.

I Application filed November 1, 1900; Serial No. 355123. (No model.)

To all whom, it may concern:

Be it known that I, NICHOLAS TOBIN, a citi= Zen of the United States,residing at Pittsburg, in the county of Allegheny and State ofPennsylvania, have invented or discovered certain new and usefulImprovements in Range-Finders, of which improvements the following is aspecification.

The invention described herein relates to certain improvements inrange-finders whereby the distance of an object of an observer may beaccurately and quickly determined.

The invention has for its object a construction of apparatus whosemedial length is a factor of the base of a triangle, the angle at theend of the base of said triangle opposite that at which the apparatus'is located having a fixed or constant value regardless of the distanceof the object, and the angular movement of the member of the apparatusactuating the dial mechanism shall be proportional to the change ofangle at the apex of said triangle'for every variation in the distanceof the object observed.

The invention is hereinafter more fully described and claimed.

In the accompanying drawings, forming a part of this specification,Figure 1 is a plan view of my improved apparatus in open position. Fig.2 is an end elevation of the apparatus, the parts thereof being in thesame positions as in Fig. 1. Fig. 3 is a sectional elevation of theapparatus. Figs. 4 and 5 are detail views of the mechanism for shiftingthe frame. Fig. 6 is an enlarged view of the dial-actuatin g slide andits shifting mechanism. Fig. 7 is a plan view of the dial-actuatingmechanism and its controller. Figs. 8 and 9 are sectional elevations onplanes indicated by the lines V'III VIII and IX IX,

Fig. 7; and Fig. 10 is a diagrammatic viewillustrating the operation ofthe apparatus.

1 is the bed-plate or base, which may be conveniently mounted upon astationary support, such as a tripod. This bed-plate or base remains ina fixed position in respect to the object the distance of which is to bedeterv mined after the apparatus has been directed to the object in themanner which I shall hereinafter explain and which is the first'step indetermining distance with my improved apparatus. Upon this bed-plate 1 aframe 2 is pivotally mounted. Both the bed plate 1 and the frame 2 arepreferably made rectangular in shape and equal in dimensions, as shownin the drawings. Frame 2 is caused to turn around a center by anysuitable driving mechanism interposed between the frame andbedp1atesuch, for example, as that shown, consisting of pinions 4 4,which are mounted .on the under side of frame 2, en-

gaging racks 5 5, mounted on the upper side of bed-plate l. The frameand bed-plate are provided also with guides 6 6 and 7 7, which engageone another. I

Two mirrors 8 and 9 are mounted upon the bed-plate 1,one of them, as 9,being so supported on a post 3, whose axis coincides with the center ofmovement of the frame, as to be in a plane passing through the medialline of the apparatus. The mirror 8 is secured on the bed-plate in frontof the mirror-9 and parallel therewith and with its reflecting-surfacefacing the mirror whose reflecting-surface faces the object to beobserved. The mirrors 8 and 9 are so arranged with reference to eachother that rays of light passing immediately over the upper edge ofmirror 8 are received on mirror 9, reflected to mirror 8, and

.again reflected, so as to pass immediately over mirror 9. This resultis best accomplished by placing mirror 9 higher above the bedplate 1than mirror 8 and inclining mirror 8, as indicated in Fig. 2. Mirror 9is provided with a sight-mark or preferably with a small spy-glass 13,placed at the middle of its upper edge. This spy-glass is provided withspider-lines, which of course serve as a delicate sight-mark. 3

The two mirrors l0 and 11 are so arranged with respect to one another onthe frame 2 that when the instrument is closed one of them, as 11, willbe in a vertical plane passing through the medial line of the apparatusand the mirror 10 parallel to the medial line of the bed-plate 1. Theyalso are arranged face to face and so inclined thata ray of light fromthe object whose distance is to be that when the instrument is closedmirrors 8 and 10 shall lie in substantially the same plane and form onepractically continuous mirror and that mirrors 9 and 11 shall lie insubstantially the same plane and form another practically continuousmirror. The mirror 11, which is pivotally mounted on frame 2, isprovided with an index, which may be the pivotal end of the mirror 11and is so situated as to be reflected in the surface of mirror 10.

It has been stated that frame 2 is pivotally mounted on bed-plate 1 andthat mirror 11 is pivotally mounted on frame 2. These two pivotal pointsare placed, as shown, at the extremities of the medial line of frame 2.Means are provided by which when frame 2 moves on its pivotal point 3mirror 11 also moves on its pivotal post 15 away from mirror l0, and therate of motion is definite, as will be hereinafter explained. Anaxle 17is mounted in suitable bearings 18 18, secured to the bed of the frame2. Upon this axle pinions l9 and 21 are mounted. Pinion 19 is adapted toengage a rack 22, fixed on bed-plate 1. This rack 22 is in the shape ofan arc of a circle and is so placed that post 3 is the center of thatcircle. Pinion 19 is preferably made slightly conical, so as to travelaccurately upon this arc-shaped rack. Pinion 21 engages a rack 23, whichis rigidly attached to mirror 11 and is movable in guides 24 24, mountedupon frame 2. Rack 23 is also arc-shaped and is so placed that thepivotpin 15 is at the center of that are. Pinion 21 also is preferablyslightly conical in shape, so as to travel accurately upon rack 23. Itwill be understood that by adjusting the relative sizes of the twopinions 19 and 21 and by adjusting their positions upon axle 17 withrespect to one another and the position of the racks 22 and 23 it ispossible to vary the rate of movement of mirror 11 upon its pivotalpoint with respect tothe rate of movement of frame 2 upon its pivotalpoint to any desired extent. In practice Iso adjust these pinions andtheir racks that the angular movement of mirror 11 shall exceed theangular movement of frame 2 (which is the same as the angular movementof mirror 10) bya certain definite amount and that this excess ofmovement shall be a relatively small fraction of the angular movement offrame 2. A third pinion 20 is secured upon the shaft 17, so as to engagea rack 25, which is mounted in aguide 26, secured to the under side ofthe frame 2. As the shaft 17 is rotated by the shifting of the frame 2the movement of the rack will be proportional to the movement of theframe, the proportion being dependent on the relative sizes of thepinions l9 and 20. The sliding rack 25 is provided at one end with aspur 27, which is made of such a length that its point will, when therack has been shifted to its extreme outward movement, be immediatelyabove or in alinement with the center of movement of an arm 28. This armhas its inner end pivotally mounted on asuitable support, such as theguide 26, on the frame 2 in suitable relation to the line or path ofmovement of the rack 25 and has its outer end connected to a slide 29,arranged at an angle to the line of movement of the rack 25. This slideis mounted in guides 30, secured to the under side of the frame 2, andis provided with a ledge 31, having its edge toothed to engage a pinion32, forming a part of a train of gearing for operating theindicating-fingers. The slide is also provided with a ledge 33,011 whichis mounted the mechanisms for shifting the slide back and forth. Adesirable construction of shifting mechanism consists of pinions 34,loosely mounted on drums 35, so as to be rotated on the drum in onedirection, but connected by pawls and ratchets to the drums when thelatter are driven in the opposite direction by their actuating-springs36. The drums are held from rotation by means of brakes 37, normallyheld against the drums bysprings 38. The brakes can be shifted and heldout of contact with the drums by fingers 39, which are accessiblethrough the bottom board of the frame. The fingers are held depressed bymeans of spring-catches 4O engaging projections on the fingers. Th'epinions 34 intermesh with a rack 41, secured to the under side of theframe 2, and their driving mechanisms are oppositely arranged, so thatone of them will shift the slide in one direction and the other in theopposite direction.

The arm 28 is provided on its inner edge with a rib 28, the inner faceof which will coincide with a plane passing through the center ofmovement of the arm. The inward movement of the arm and also that of thedial-actuating slide 29 is regulated by the position of the spur 27 onthe rack 25. As the rack is shifted by the frame the movement of theindicating-dials will be proportional to the movement of the frame.

The pinions 4, which are employed for shifting the frame back and forth,are drawn by spring-actuated drums 35, similar to the constructionheretofore described. The rotation of the drums is controlled byspring-actuated brakes 37, which are moved away from the drums byhandles 43, which are preferably located at the edge of the frame andconnected to the brakes by rods 44, as shown in Fig. 1. These drivingdevices are oppositely arranged, one being employed to move the frameand the other to shift it to closed position.

The operation of my apparatusis as follows: The apparatus closed inpositionthat is, having mirrors 8 and 10 and 9 and 11 alinedis placedupon its support, and the object the distance of which from the observeris to be determined being selected the instrument is so placed that theobserver, looking through the spy-glass 13 or sighting upon a sight-markplaced in the same position, shall see the object reflected from mirrorSand shall bring the image of that object into alinement with thesight-mark. Having done this, the position of frame 1 is fixed for theobservation. The operator then shifts one of the handles 43,

of the frame.

stapes 3T releasing one of the frame-shifting devices, so as to turn theframe 2 upon its pivotal center. It being understood that mirror 11travels slightly more rapidly that mirror 10, the frame 2 is revolveduntil the observer, looking in the mirror 10 over a mark or smalltelescope on a convenient part of the instru ment, as above thepivot-point 15, where the image of the object and the point 15 can beseen in the mirror 10, will see the image of the object reflected frommirror 11 moving along mirror 10 toward the left until such image of-theobject coincides with the reflection in mirror 10 of the indicator onmirror 11, which in the construction shown is the left-hand end of themirror 11. When this alinement of the image of the object with the endof mirror 11 reflected in 10 has been efiected, the operator releasesthe handle 44:, thereby checking the movement of the frame. Prior toshifting the frame the slide 29 should be in the position shown in Fig.7. By the turning movement of the frame 2 the rack 25 is moved in thedirection of the arrow at a distance proportional to the outwardmovement As soon as the movement of the frame is stopped the operatordepresses one of the fingers 39, so that the slide 29 will be moved tothe left, actuating the indicating-dials until arrested by the rib 28 onarm 28, striking against the spur 27 on the rack 25. As soon as themovement of the slide 29 is arrested the operator can read the distanceof the object observed on the dials.

In constructing my improved range-finder I take a triangle, preferably aright-angled triangle, having a base which is a multiple of the mediallength of the apparatus or the distance between the pivotal center ofthe frame and the pivotal center of the mirror 11 and whose apex is atthe object-as, for example, if the apparatus has a medial length of twofeet the base of the triangle will have a length of seven hundred andtwenty feet or any other length of whichtwo is an exact divisor. Themirrors 10 and 11, which might properly be termed focusing-mirrors, areso arranged and shifted in relation to each other that when the imagesof the object and the indicator on mirror 11 have coincided in mirror 10a given point on the frame will have moved an angular distance from agiven point on the base-plate, said. points coinciding or registeringone with the other when the mirror 11 is parallel with mirror 9, suchangle having a certain fixed relation to the angle at the object or atthe apex of the triangle having the given'baseas, for example, in theconstruction shown the edges 0. and b of the frame and base-platecoincide or register with each other and when the instrument is closedlie in a plane passing through the center of movement of the frame andmay be taken as reference-points, above referred to. When the apparatushas been sighted on the object by mirror-s8 and 9 and focused byshifting the frame, as above described,

the edge a, of the frame will be at an angle to the edge b of thebaseplate, and the apparatus is so constructed that the angle a c b willhave a certain fixed relation to the angle at the apex of theright-angled triangle. It is preferred to so construct the apparatusthat when focused the angle will equal the angle 10, 0 p at the apex 0of the right-angled triangle, whose base is a multiple of the mediallength of the instrument.

By reference to Fig. 10 it will be seen that the angle a c b, formed bylines passing through the reference points or edges (1 b and the axis ofmovement of the frame, is equal to the angle n 0 p and that the angle ac b is equal to the angle n 0' p.

The frame 2 in'its movement shifts the spur or stop 27 a'distanceproportional to its angular movement. The position of the spur 27determines the movement of the slide 29, which actuates the indicatingmechanism of the apparatus. The indicating mechanism is so constructedin accordance with rules known in the art that for every'chango ofposition of the frame 2 the dial will indicate the corresponding changein the distance of the center 0 of the apparatus to the object.

I claim herein as my invention 1. A range-finder having a medial lengthwhich is a factor of the base of a right-angled triangle in combinationwith a member movable on a center, which forms one terminus of the baseof said triangle, a distance-indieating mechanism controlled by themovable member and focusing mechanism for determining the range ofmovement of the movable member, substantially as set forth.

2. A range-finder having in combination two movable mirrors arranged sothat the image of an object will be reflected from one to the other,means for shifting said mirrors one at a greater speed than the other tobring the image of an indicating-mark reflected in one mirror intoindicating relation to the image of a distant object reflected in bothmirrors, and an indicating mechanism operated in accordance with themovements of the mirrors, substantially as set forth.

3. A range-finder having in combination a base, a frame pivotallymounted on the base, a mirror secured on said frame, a second mirrorpivotally mounted on the frame, means for shifting the frame, meansshifting the second mirror independent of the frame and an indicatingmechanism movable independent of but controlled by the movement of theframe, substantially as set forth.

4. A range-finder having in combination a base, a frame pivotallymounted on the base, a mirror mounted on the frame, a second mirrorpivotally mounted on the frame, means for shifting the frame,connections from the frame to the second mirror whereby the latter maybe shifted at a greater speed than the frame, and an indicatingmechanism operated by the frame, substantially as set forth.

5. A range-finder having in combination a ICC base,aframe pivotallymounted on the base,a ent rates of speed, a slide operated by the mirrorcarried by the frame, means for shiftframe, a stop carried by the slide,a springing the frame, a second mirror pivotally actuated slide and anindicating mechanism [5 mounted on the frame and movable thereby,operated by the slide, substantially as set 5 a stop device operated bythe frame and a forth.

spring-operated indicating mechanism con- In testimony whereof I havehereunto set trolled by the stop, substantially as set forth. my hand.

6. A ran e-finder having in combination a base, a fran ie pivotallymounted on the base, a NICHOLAS TOBIN 10 mirror carried by the frame, asecond mirror Witnessesi pivotally mounted on the frame, means for F. E.GAITHER,

moving the frame and second mirror at difier- F A. DANNER,

